The present invention relates generally to optical modulators, and, more specifically, to high bandwidth optical modulators.
Data transmission is accomplished using amplitude and/or phase modulation of an optical signal, such as a laser beam, for encoding the data, which is then transmitted through a fiber optic waveguide, for example. The rate at which data can be transmitted is fundamentally limited by the speed at which the optical signal can be modulated.
One type of optical or light modulator utilizes an acousto-optic effect in order to modulate a propagating light or signal beam. The signal beam is scattered off an orthogonally traveling sound wave due to the densification of a material in the presence of an applied acoustic field. The rise time for this phenomenon is on the order of nanoseconds. The rise time limits the bandwidth for such acousto-optic modulators to about several hundred megahertz.
In recent developments, electro-optical devices are based on novel materials and have demonstrated potential modulation bandwidths up to hundreds of gigahertz. However, these devices require millimeter-wave electronic drivers which are prohibitively expensive and complicated.
Accordingly, it is desired to provide an optical modulator which is relatively simple in construction and operation, and is effective for increasing modulation bandwidth orders of magnitude greater than conventional modulators to allow several generations of increase in the rate at which data can be transmitted.